The cold and dryness of winter present a dual challenge for patients with chronic kidney disease. Low temperatures make it harder to control the balance of water and salt, while indoor heating dries the air, often leading to thirst and a dry throat. Additionally, winter diets tend to be higher in salt, which inadvertently increases the burden on the kidneys. So, how can one drink water scientifically during winter? Experts from Kuangjie offer some practical advice to help kidney patients stay healthy during the cold winter months.
General Principle for Water Intake: Strict Salt Control Personalized Fine-Tuning
When kidney function is impaired, excessive water intake may lead to water overload, blood pressure fluctuations, and even conditions such as hyponatremia, pulmonary edema, and heart failure. Conversely, insufficient water intake may induce constipation, dry mouth and throat, and even low perfusion and elevated serum creatinine. So, how much water should one actually drink?
The general principle for drinking water in winter
1. Strict sodium restriction (≈ table salt ≤5g/d);
2. On this basis, fine-tune by combining urine volume, symptoms, and signs.
What to Drink: Choosing the Right Beverage
Patients with kidney disease should primarily choose warm plain water, minimize consumption of carbonated water and functional beverages, and consume tea or coffee in small amounts, which should be included in the total fluid intake. It is advisable to reduce sugar and milk intake. Beverages such as coconut water, thick soups, and fruit juices contain both water and potassium, sugar, and sodium, so individuals with chronic kidney disease, especially those in advanced stages or on dialysis, should use them with caution.
How much to drink: How to master the amount of water
01 How to Determine If You Are Drinking Enough Water
First, observe the weight trendAfter emptying the bowels and bladder in the morning on an empty stomach, weigh yourself on the same scale: If there is a short-term continuous increase, with a daily increase of ≥0.5-1.0kg, it indicates excess.
Second, observe physical signs and breathing,If symptoms such as ankle depression, worsening edema, elevated blood pressure, chest tightness, shortness of breath, or even wheezing occur, it indicates an overdose, and severe symptoms require immediate medical attention.
Third, observe urine volume and colorIf the amount is significantly reduced and the color is dark, it often suggests that the intake of water can be appropriately increased.
02 Water Intake for Patients at Different Stages of Renal Function
Chronic Kidney Disease Stage 1-2 (Glomerular Filtration Rate ≥60 mL/min/1.73 m²):If urine output is normal, there is no edema, and blood pressure is relatively stable, the total daily fluid intake (including plain water, soups, porridges, beverages, and "hidden water" in fruits and vegetables) is generally consistent with that of healthy individuals: approximately 1500-2000 mL. The prerequisite is to limit salt intake (no more than 5 grams of salt per day). By controlling salt, thirst is reduced, making it easier to manage fluid intake.
Chronic kidney disease stage 3-4 (glomerular filtration rate 15-59 mL/min/1.73m²):Refer to the formula: Today's total fluid intake ≈ yesterday's urine output + 500mL (if the environment is hot, there is fever, or excessive sweating, it can be increased to 600mL). Then, adjust slightly up or down by 200-300mL daily based on weight trends, ankle edema, and blood pressure.
Stage 5 chronic kidney disease (glomerular filtration rate <15mL/min/1.73m²):Some patients experience a significant reduction in urine output. The principle is "better safe than excessive." It is essential to first control salt intake, then carefully manage fluid intake under medical guidance to avoid edema caused by "intake exceeding output." If necessary, adjust diuretics or dialysis plans as directed by a doctor.
03 Dialysis Patient Water Intake
Patients undergoing hemodialysis should aim for an inter-dialytic weight gain (IDWG) ≤ 2-3% of their dry body weight (or ≤ 2-3 kg, whichever is smaller) as a baseline. If this limit is frequently exceeded, it is usually due to excessive "salt load and unrestricted fluid intake," necessitating adjustments in dietary sodium and ultrafiltration strategies. Peritoneal dialysis is relatively stable, but the general principle remains the same: prioritize sodium restriction and fine-tune fluid intake based on body weight, edema, blood pressure, and ultrafiltration volume.
More importantly, whether it is hemodialysis or peritoneal dialysis, it is essential to communicate regularly with the supervising medical staff.
How to Drink: Water Drinking Tips for Kidney Disease Patients
01 Practical Tips for Drinking Water
Record daily water intake; drink slowly in small sips, avoid gulping; roughly allocate water intake in the morning, noon, evening, and night in a 3:3:2:2 ratio, stop drinking water 2-3 hours before bedtime to help reduce nighttime urination; avoid ice water, prefer warm water; maintain indoor humidity, do not drink immediately after returning home from outside, observe first and then rehydrate.
02 How to Calculate "Invisible Water"
"Invisible Water" = the sum of all water content other than plain water, including soup, porridge, dairy products, beverages, fruits, vegetables, etc. Specifically, a bowl of soup or porridge, or a small cup of beverage ≈ 300-400 mL of water. Fruits such as watermelon and oranges have a water content of up to 85%-90%. Vegetables such as cucumbers, tomatoes, and lettuce also have a high water content, approximately 80%-90%. These should all be counted toward daily fluid intake, especially for patients with edema, oliguria, or heart failure, where proper management of invisible water is important.
03 How to Limit Salt Intake Easily
Limiting salt intake reduces thirst, making it easier to control water consumption. You can make salt restriction easier by following these steps
1. Set a goal: Limit daily salt intake to about 5 grams (sodium < 2 grams);
2. Gradual progression: Reduce salt intake by 20% in the first week; reduce by another 20% in the second week; aim to approach ≤5g/day by the third week;
3. Use measuring spoons and limit total amount - when cooking, use measuring spoons and a "salt limit jar" to weigh out the day's salt first, distribute it by meal, and stop when it's used up;
4. Avoid high-salt foods;
5. Skillfully use flavor substitutes, such as replacing heavy saltiness with "sour, fragrant, spicy, and fresh" flavors (lemon/rice vinegar, scallions, ginger, garlic, a small amount of spiciness).
6. Timely Feedback – Measure blood pressure and weigh yourself every morning: reduced thirst, decreased nighttime urination, and stable blood pressure indicate you are on the right track. Additionally, it is important to note that most "low-sodium salt" contains potassium, so individuals with advanced CKD or high potassium levels should exercise caution.
If these signals appear, seek medical attention immediately
1. Significant edema, sudden weight gain of ≥2kg in a short period, chest tightness and shortness of breath, or even orthopnea;
2. Sudden decrease in urine output (<400 mL/d) or anuria;
3. Blood pressure remains consistently higher in the morning than usual; 4. Rapid increase in creatinine/potassium levels; 5. High fever accompanied by vomiting/diarrhea, indicating a high risk of volume or electrolyte imbalance, and immediate medical attention is required.
